Pacteau initially told detectives - who identified him on CCTV footage - they had consensual sex at his flat and she had fallen and injured herself on the bed frame.

Ms Buckley, a qualified nurse from Cork, had moved to Glasgow to study a masters degree and had only been living in the city for a few months before she was killed.

Her parents John and Marian - who travelled from Cork to see Pacteau plead guilty on August 11 - appeared in court again for his sentencing.

It emerged Pacteau stood trial in 2013 at the High Court in Paisley accused of attempting to rape a woman but was found not guilty.

PA

Karen Buckley's parents were in court for Pacteau's sentencing

Our little angel has been taken from us forever in the cruellest of ways

Karen Buckey's father

He met Ms Buckley in the early hours of April 12 outside Sanctuary nightclub and drove her to nearby Kevin Way, where he grabbed her by the neck and delivered around a dozen blows with a spanner.

Pacteau attempted to dispose of her body in a bath at his flat with a vat of chemicals he bought at various shops.

He then burned a mattress and clothes at Craighton Farm on outskirts of the city before locking a barrel containing Ms Buckley's body in a storage unit he had rented.

Pacteau's solicitor John Scullion QC said he could offer no "rational explanation" for his actions.

A statement issued on behalf of Ms Buckley's family said: "Today's life sentence will not bring our beautiful Karen back. Our little angel has been taken from us forever in the cruellest of ways. We mourn for her every day.

"It will however ensure that women are safe from harm from the truly evil coward who took our beautiful Karen's precious life. I hope that he is never released and spends every day in prison haunted by what he did.

"Karen is at peace now and we know that she is in heaven looking down on us and helping us."